See David Speyer's thread

http://tea.mathoverflow.net/discussion/741/does-lim-cosn-exist/

which is about a closed question involving limit points of $\cos (n!)$ which is to say values of $n! \pmod {2 \pi},$ or in turn values of
$$ \frac{n!}{2 \pi} \pmod 1. $$
David's conclusion, evidently posted on math.stackexchange, is that we do not know enough about $\pi$ to answer this.